Robotic-assisted surgical systems have been developed to improve surgical precision and enable the implementation of new surgical procedures. For example, robotic systems have been developed to sense a surgeon's hand movements and translate them to scaled-down micro-movements and filter out unintentional tremors for precise microsurgical techniques in organ transplants, reconstructions, and minimally invasive surgeries. Other robotic systems are directed to telemanipulation of surgical tools such that the surgeon does not have to be present in the operating room, thereby facilitating remote surgery. Feedback-controlled robotic systems have also been developed to provide smoother manipulation of a surgical tool during a procedure than could be achieved by an unaided surgeon.
However, widespread acceptance of robotic systems by surgeons and hospitals is limited for a variety of reasons. Current systems are expensive to own and maintain. They often require extensive preoperative surgical planning prior to use, and they extend the required preparation time in the operating room. They are physically intrusive, possibly obscuring portions of a surgeons field of view and blocking certain areas around the operating table, such that a surgeon and/or surgical assistants are relegated to one side of the operating table. Current systems may also be non-intuitive or otherwise cumbersome to use, particularly for surgeons who have developed a special skill or “feel” for performing certain maneuvers during surgery and who find that such skill cannot be implemented using the robotic system. Finally, robotic surgical systems may be vulnerable to malfunction or operator error, despite safety interlocks and power backups.
Spinal surgeries often require precision drilling and placement of screws or other implements in relation to the spine, and there may be constrained access to the vertebrae during surgery that makes such maneuvers difficult. Catastrophic damage or death may result from improper drilling or maneuvering of the body during spinal surgery, due to the proximity of the spinal cord and arteries. Common spinal surgical procedures include a discectomy for removal of all or part of a disk, a foraminotomy for widening of the opening where nerve roots leave the spinal column, a laminectomy for removal of the lamina or bone spurs in the back, and spinal fusion for fusing of two vertebrae or vertebral segments together to eliminate pain caused by movement of the vertebrae.
Spinal surgeries that involve screw placement require preparation of holes in bone (e.g., vertebral segments) prior to placement of the screws. Where such procedures are performed manually, in some implementations, a surgeon judges a drill trajectory for subsequent screw placement on the basis of pre-operative CT scans. Other manual methods which do not involve usage of the pre-operative CT scans, such as fluoroscopy, 3D fluoroscopy or natural landmark-based, may be used to determine the trajectory for preparing holes in bone prior to placement of the screws. In some implementations, the surgeon holds the drill in his hand while drilling, and fluoroscopic images are obtained to verify if the trajectory is correct. Some surgical techniques involve usage of different tools, such as a pedicle finder or K-wires. Such procedures rely strongly on the expertise of the surgeon, and there is significant variation in success rate among different surgeons. Screw misplacement is a common problem in such surgical procedures.
Image-guided spinal surgeries involve optical tracking to aid in screw placement. However, such procedures are currently performed manually, and surgical tools can be inaccurately positioned despite virtual tracking. A surgeon is required to coordinate his real-world, manual manipulation of surgical tools using images displayed on a two dimensional screen. Such procedures can be non-intuitive and require training, since the surgeon's eye must constantly scan both the surgical site and the screen to confirm alignment. Furthermore, procedural error can result in registration inaccuracy of the image-guiding system, rendering it useless, or even misleading. Thus, there is a need for a system for stabilizing surgical instruments while allowing the instruments and the instrument holder to be both easily sterilized and installed and removed from the robotic system without deteriorating localization precision as well as attachment rigidity.